Abstract: Kick tolerance is an indicator of evaluating the ability to deal with kick during drilling. It plays a very important role in casing program design, drilling and well control operation.However,due to the influence of multiple factors, such as fluids properties, the pressure capacity of casing shoe, the definition and calculation method are not uniform, which directly affects the rationality of well structure design and the safety of well control process. In this paper, based on the theory of continuous gas column and the well killing program of driller's method, and by taking into account kick intensity and drill tools size, the definition and computing model of kick tolerance are modified.The modified model can effectively improve the computational accuracy of the kick tolerance, and provides a guarantee for safe and fast drilling. The modified model has been used in a well in the south China sea. The result shows that the modified model can further improve the calculation accuracy of kick tolerance. Based on the drilling data of the well, the affects law of well depth and mud density on the kick tolerance are figured out and the influences of the kick tolerance on the drilling length of single open hole are also analyzed.